Police seized drugs worth almost £2 million on the streets after they disrupted a drug-dealing operation in West Lothian.
The organiser of the West Lothian end, Ryan Mayberry, was detained along with his English counterpart Patrick McKervey.
Hugh McAnna, 52, who acted as a money courier, and Gordon Stewart, 50, who was a drugs mule, were also arrested.
Advocate Leanne Cross told the High Court in Edinburgh that Mayberry, 33, and McKervey, 31, organised and managed a number of couriers.
The advocate depute said a total of 392 kilos of cannabis were recovered, which could be broken down into street deals worth up to £928,000.
A further ten kilos of high-purity amphetamine were seized, which if cut could be bulked out for street sale with a maximum value of £950,000.
Mayberry, of Raeburn Rigg, Livingston, McKervey, of Parkville Highway, Coventry, McAnna, of Harthill Road, Fauldhouse, and Stewart, of Loch Trool Way, Whitburn, admitted charges today.
All four will be sentenced next month.